Mosquitoes hate the taste and smell of the anti-insect Deet. But that's not because they prove it with their heads, but with their legs.
Researchers at Rockefeller University in New York discovered that. They published their research this week in the scientific journal Current Biology.
"A first step"
But how useful is that we know that? "It's especially interesting because we've known this drug for a long time, about seventy years," says Bart Knols. He did not take part in the research, but is an entomologist at Radboud University and wrote the book "Mug & # 39; "200 million people use the drug annually."
"We just knew it worked all the time, but not how." Knols calls the search "a first step to unraveling Deet's workings". "And if we extend this positively: this research can help find new drugs that work well against mosquitoes as well."
How did they find out?
The researchers came to this conclusion by rubbing the guinea pigs with Deet and putting on special gloves. The gloves had small holes, so that the mosquitoes could not reach the skin with their feet, but with the head.
What the researchers saw at the time was that Deet no longer allowed mosquitoes to stop.
The researchers then rubbed the legs of the mosquitoes with a special glue, which made their taste sensors no longer work properly. Even so, the mosquitoes were not prevented by Deet.
Because, admittedly: Deet is an "intense" tool, says the entomologist. "It's one of the most important defenses: when you have on your skin, almost no mosquito lands. But it's also a bit of an aggressive substance."
It's not like plastic: "If you mess with Deet in his plastic sunglasses, it melts." It has also been known for some time that 20% of Deet ends up in the bloodstream. "Therefore, you should not use it with children, and it is not good as an adult if you wear it day after day every year."
There are already green alternatives on the market that, according to Knols research, work as well as Deet (the 20% version). "A lime eucalyptus-based repellent that has been processed."
Scientists can include the new search results in follow-up surveys. "If you're going to do tests on new substances, it's good to know that mosquitoes can" prove "viable substances with their legs."
With his arms in a box
How are these remedies tested? Very simple, says the entomologist. "Test participants rub their arms and put them in a box of mosquitoes." And then it depends only on how fast they are chopped. Knols: "If you have a good medicine like Deet, then you're lucky."